A semiconductor manufacturing device, such as a film forming device (e.g., CVD device or PVD device) or a plasma etching device, is used to form a semiconductor device. Such manufacturing devices include a temperature adjustment device that adjusts the temperature of a substrate (e.g., silicon wafer) in a pressure-reduced chamber. For example, an electrostatic chuck (ESC) is used as a temperature adjustment device. The electrostatic chuck has an electrostatic chuck plate bonded on a base plate. Japanese Laid-Open Patent Publications No. 11-8290 and No. 2008-166509 describe examples of the electrostatic chuck plate. For example, the electrostatic chuck plate includes an electrode capable of attracting a substrate and a heating element controlling the temperature of the subject to be attracted (i.e., substrate). The temperature of the substrate attracted on the electrostatic chuck plate is adjusted by a coolant flowing through a conduit formed in the base plate and the heating element incorporated in the electrostatic chuck plate.
The heat density may vary in the heating element incorporated in the electrostatic chuck plate. Such variation in the heat density causes variations in the temperature of the substrate. This may vary, for example, the etching rate of the plasma etching device and thereby lower the yield of the semiconductor device.